The transportation of hazardous and radioactive materials (collectively “hazardous material”) often requires the use of cargo containers, trailers, railcars, and the like. To encourage efficient transportation with minimal ecological impact, the United States Department of Transportation regulates the transportation and storage of these materials by requiring minimal design safety criteria. See 49 CFR (incorporated by reference and collectively referred to herein as “DOT Design Criteria”). Similar regulations are enforced throughout much of the world, including IAEA International.
Cargo containers designed to transport hazardous material must be certified for such use. Certification requires meeting or surpassing testing requirements such as the free drop test and the stacking test as required by 173.410; 173.411; 173.465; and 173.466. During the free drop test, the cargo container is loaded to its design capacity and dropped from a specified height. Upon impact, the cargo container must maintain its structural integrity sufficiently to contain its testing contents. Powdered chalk is often used within the cargo container while testing as a benign indicator of the ability of the container to contain hazardous materials. In addition, the cargo container may be subjected to a stack test to verify its ability to contain cargo under significant compressive force for storage or final disposition.
Rigorous certification presents significant design hurdles and tradeoffs. For instance, the costs associated with designing and building cargo containers with such structural integrity are significant. After all, hazardous material cargo containers often include relatively complex design characteristics and increased quality control during manufacturing. Thus, a significant amount of time, money, and resources is typically expended to design and build the cargo container for transport of hazardous materials. However, many of the cargo container features are not certified for reuse after the initial transportation of hazardous material is complete. Thus, the cargo container is discarded and another is purchased requiring additional time, money, and resources.
Moreover, cargo containers certified for transporting hazardous materials often include complicated latches and sealing mechanisms to both seal and lock the containers. Unfortunately, complicated sealing mechanisms require additional expense and complicate their use as well as training and time to operate. Such designs often increase the likelihood of user error and elevated worker exposure to radiation while preparing the cargo container for transport of hazardous materials.
Additionally, shippers often transport a wide variety of goods, only some of which are hazardous materials. A shipping company's inventory of cargo containers typically includes a wide variety of container sizes and designs, many of which may not be rated or compatible for the transport of hazardous materials. The significant cost of known hazardous material cargo containers may prove prohibitive for a shipping company to purchase an inventory of such containers and it would be advantageous if existing cargo containers could be modified or retrofit to meet and pass the above described testing for certification to transport hazardous materials.
Thus, there is a need for a cargo container for use in transporting hazardous materials that addresses present challenges and characteristics such as those discussed above and others.